The test is composed of two main parts (part A & part B). Part B differs from Part A specifically in that it assesses more complex factors of motor control and perception [1]. Part B of the Trail-Making test consists of multiple circles containing letters (A-J) and numbers (1-13). The participant’s objective for this test is to connect the circles in order, alternating between number and letter (e.g. 1-A-2-B) from start to finish [2]. The participant is required not to lift their pencil from the page. The task is also timed as a means of assessing speed of processing [3] . Set-switching tasks in Part B have low motor and perceptual selection demands, and therefore provide a clearer index of executive function [1]. Throughout this task, some of the executive function skills that are being measured include impulsivity, visual attention and motor speed [3].

References

↑ 1.01.1Arbuthnott, K., Frank, J. (2000). Trail making test, part B as a measure of executive control: validation using a set-switching paradigm. Journal of Clinical and Experimental Neuropsychology. 22(4); 518-528